Centering guides for disc grinders



Oct. 8, 1957 I R 5;, PRICE 2,808,685

CENTERING GUIDESFOR DIS C GRINDERS Filed Sept. 15, 1955 7 2 Sheets-Sheet 2 a IFIEPRIcE INVENT OR I BY ATTORNEY CENTERING GUIDE FOR DISC GRINDERS Ralph E. Price, Beloit, Wis., assignor to Gardner Machine Company, Beloit, Wis.

Application September 15, 1955, Serial No. 534,579

14 Claims. (Cl. 51-118) The following description relates to novel centering guides for disk grinders.

Specifically the problem is presented of simultaneously grinding both ends of a gear or similar work piece between the faces of two abrasive discs. The work pieces are presented and carried between the abrasive discs by means of a rotary carrier such as a wheel or the like. The carrier has pockets in the edge or periphery to receive the individual work pieces. The pieces are held within the pockets by some suitable means such as an endless chain belt.

The work pieces are received in the pockets of the carrier without regard to their relative lateral position with respect to the abrasive discs. As a consequence one abrasive disc may be forced to remove more material from one end of the work piece than the other abrasive disc will from the opposite end of the work piece.

One object of my invention is to shift the work piece laterally of ,the carrier so that it will receive equal treatment by both abrasive discs.

A further object of my invention is to provide centering means which will operate independently of any fixed guides.

A still further object of my invention is to provide centering guides with resilient means actuated by the work piece itself and moving the work piece with a force directly dependent upon the extent to which the work piece is presented with its opposite ends unequally distant from the center line of the grinding operation.

Other objects of the invention will be apparent from the following description and the accompanying drawings.

For purposes of illustration I have shown the preferred form of my invention in the accompanying drawings in which:

Fig. l is an end elevation of the improved centering guide on a work feeder taken on the line 11 of Fig. 2;

Fig. la is an enlarged fragmentary elevation;

Fig. 2 is a side elevation of the assembly; and

Fig. 3 is a horizontal section taken on the line 3---3 of Fig. 2.

Figure 4 is a partial view showing the relation between the teeth on the carrier and the chain for holding workpieces between said teeth.

Briefly described, I have provided means for shifting a work piece such as a gear or the like laterally of the carrier by which it is presented centrally between two spaced abrasive discs. The centering means consists of a pair of symmetrically disposed bell crank levers which can be shifted as a whole laterally of the carrier and the center line of the space between the two abrasive discs. The end of one of the bell crank levers is connected to the other by two flat leaf springs so arranged as to allow radial diplacement only, so that movement of one bell crank lever causes an equal movement of the other bell crank lever. The other ends of the bell crank levers carry guide shoes through which the work piece must pass before being clamped in the carrier. The ends of the bell crank levers which carry the guide shoes are urged Fatented Oct. 8, 1957 together by means of a tension coil spring. In this way,

the guide shoes are forced open by the passage of the work piece sufiicient only to allow the work piece to pass through. Due to the equalized movement of the two shoes the center line of the space between the shoes is in constant relation to the centerline of the spacebetween the abrasive discs regardless of the amount of opening required between the shoes for the passage of the work. When passing between the shoes the work piece will be shifted laterally as required to bring equal pressure to bear on each shoe due to the effort of the tension coil spring and thereby cause the work piece to become equally spaced with reference to the two abrasive discs. The latter will remove an equal amount of stock from the opposite ends of the work piece.

In the drawings, a carrier wheel 6 has been shown as mounted upon a rotating shaft 7. The wheel 6 passes within the orbit of the abrasive discs 8 and 9. The latter are positioned with their inner flat surfaces spaced from each other a distance equal to the desired width of the completed work pieces. Abrasive discs are rotated on individual spindles (not shown).

The carrier 6 has a series of pockets 10 each of which is of a size to receive the work piece being operated upon. A chute 11 is provided to feed work pieces such as gears 12 in timed sequence to fill the pockets 10 as they pass the end of the chute.

The work pieces 12 are retained in the pockets 10 during the grinding operation by means of a chain or similar band 13. This travels over an idler 14. After passing out of the orbit of the discs 8 and the chain 13 travels tangentially away from the carrier 6 and permits the finished work pieces to fall away by gravity.

The grinding machine includes a base 15. This serves as a support for a bracket 16 which may be shifted laterally to and from the carrier 6 as shown in Fig. 1. The bracket 16 has a slide 17 which is given an independent lateral adjustment on the bracket. This is accomplished by provision of a bearing 18 on the bracket. The bearing carries a revolvable adjusting screw 19 which engages a screw threaded opening in the rear of the slide 17.

The bracket 16 has a guide plate 20 on its front face parallel to and slightly spaced from one side of the carrier 6.

The adjustable slide 17 has a second guide plate 21 which may be brought into position on the opposite side of carrier 6. It is desirable to have the plates 20 and 21 equally spaced from the carrier 6. work pieces 12 will fall into the pockets 10 between the guide plates 20 and 21 and approximately centered with respect tothe abrasive discs 8 and 9.

However, it is desirable to shift the work pieces laterally in the pockets so that the centering operation is as perfeet as possible, and thus the extent of grinding equalized between the two ends of the work pieces. For this purpose the slide 17 carries an arm 22 which projects transversely over the carrier 6 andabove the guide plate 21.

The slide 17 carries a journal bearing 23 well back from the plane of the carrier 6. The arm 22 has a similar journalbearing 24- equally distant from the plane of the carrier 6 and on the opposite side thereof. Each journal bearing 23 and 24 carries a loose shaft 25, 25 provided with anti-friction bearings to permit ready pivotal movement of the shafts.

. Each shaft 25 carries a bell crank lever 26, 27. These levers are mounted in a plane at right angles to that of the carrier 6 and beyond the guide plates 20 and 21.

The lever 26 has a depending or lower arm 28, while a symmetrically disposed lower arm 29 forms part of lever 27. The end of each lower arm 28, 29 is provided with a guide plate 39, 36. These guide plates are made In this way the.

of wear-resistant material. They are also sloped or convergent at their front edges, as shown in Fig. 3.

A coil spring 31 under tension connects pin 32, 32 on the arms 28, 29.

Each bell crank lever 26, 27 is provided with a horizontal arm 33, 34 respectively. These arms extend substantially in the horizontal line connecting the shafts 25, 25. The free ends of horizontal arms 33, 34 are provided with upstanding vertical leaf springs 35, 36 respectively. The upper free ends of the springs are fastened together by means of a clamp 37.

As pointed out above, the work pieces 12 drop into the individual pockets in random positions. The adjusted distance between the guide plates and 21 is insufficient to provide accurate centering of the work pieces. However, each work piece will readily pass between the open, converging edges of the guide plates 30, 38. If the engagement with the face. plates is unequal, the work piece will force one arm to be displaced open to allow ntrance and the other arm will be forced open an equal amount due to the vertical leaf springs which tie the horizontal arms of the bell crank together. The force of the tension coil spring which urges the guide plates together will cause a lateral shift of the workpiece until both guide plates are allowed to come together and press equally. on: opposite. ends of the workpiece. At this point the. chain 13 begins. to bear upon the outer edge of the work piece and holds it firmly in the pocket 10. This engagement is maintained throughout the orbital distance of travel of the carrier 6 between the abrasive discs 8 and 9. During this movement the chain 13 rests within a peripheralgroove in the carrier 6;

Due. to the central position of the work piece as it passes. between the abrasive discs 8 and 9, the grinding fiectupon opposite ends of the work piece is equalized, and the same amount of material removed from each end.

While I have shown and described the preferred form of; the invention, it will, be readily understood that many changes may be made in minor details, material and proportionsgwithout departing from the scope of the invention: asset out in the following claims.

I: claim:

1. In combination with a movable work-holding carrier, for carrying work pieces through a machine, a fixed guide. plate adjacent each side of the carrier, a pair of levers; a journal for each lever at an intermediate point, a support, a pair of spaced hearings on said support for said: journals, said levers having horizontal arms with contiguousjf'ree ends, means for attaching said free ends together whereby rotation of one of said levers effects rotation of the other in-the opposite direction, a depending arm on each' lever, a spring connecting said dependingarmsfor urging them into contact with a work piece, and a guide plate on the end ofeach depending arm for engaging a work piece on the carrier.

21 In combination with a rotating work-holding pocke-ted carrier for carrying work pieces through a machine, a fixed guide plate adjacent each side of said carrier opposite its'pockets, a pair of levers, a journal for each lever at an intermediate point, a support, a pair of spaced hearingson said support for said journals, said levers having" horizontal arms with contiguous free ends, a spring attached to each arm, a clamp for the ends of the springs, a depending arm on each lever, a spring connecting said depending arms for urging them inwardly to ward one another, and a-guide plate on the end of each depending arm engaging a work piece on the carrier.

3;: In combination with a rotating work-holding pocketed,carrierforrcarrying work pieces? through a machine, a fixedjguide plate adjacent each sideofsaid carrier op.- ppsite its pockets, a pair of-bell.crank levers, a pivot shaft-for eachylever, a support, a'pair of spaced bearings on,;said..support for said-shafts, said levers having-horizontal armswith contiguousfree ends, a spring attached to each arm, a clamp for the ends of the springs, a depending arm on each lever, a spring connecting said depending arms, and a guide plate on the end of each depending arm engaging a Work piece on the carrier.

4. In combination with a rotating work-holding pocketed carrier for carrying work pieces through a machine, an adjustable fixed guide plate adjacent each side of said carrier opposite its pockets, a pair of bell crank levers, a pivot shaft for each lever, a movable support, a pair of spaced hearings on said support for said shafts, said levers having horizontal arms with contiguous free ends, a spring attached to each arm, a clamp forv the ends of the springs, a depending arm on each lever, a spring connecting said depending arms, and a guide plate on the end of each depending arm engaging a work piece on the carrier.

5. In combination with a rotating work-holding pocketedcarrierfor carrying work pieces through a machine, a fixed guide plate adjacent each side of said carrier opposite its pockets, a pair of levers, a journal for each lever at an intermediate point, a support, a pair of spaced bearings on said support for said journals, said levers having-horizontal arms with contiguous free ends, a leaf spring attached to each arm, a clamp for the ends of the springs, a depending arm on each lever, a tension spring connecting said depending arms, and a guide plate on the end of each depending arm engaging a work piece on the carrier.

6. Incombination-with'a rotating work-holding pocketed carrier for carrying work pieces through a machine, a fixed guide plate adjacent each side of said carrier opposite its pockets, a pair of levers, a journal for each lever at an intermediate point, a support, a pair of spaced bearings on said support for said journals, s'aid levers hav'inghorizontabarms with contiguous free ends, a leaf spring, attached to' each arm, a clamp for the ends of the springs, a depending arm on each lever, a tension spring connecting said' depending arms, and a guide plate on the' end of each depending arm opposite the adjacent end of a fixed guide plate and engaging a work pie'ceon the carrier.

7. In combination with a rotating work-holding pocketed'carrier for carrying work pieces through a machine, a fixed guide plate adjacent each side of said carrier opposite itspockets, a pair of levers, a-journal for each lever at an intermediate point, a support, a pair of spaced bearings on said support for said journals, said levers having horizontal arms with contiguous'free ends, a leaf spri'ng'attached to each arm, a clamp for the-ends of the springs, a depending arm on each lever, a-tension spring connecting said depending arms, and a guide plate" on the end of each depending arm, said guide plates having flaring side' edges opposite the adjacent edges of the fixed guide-plates for engaging a work piece on the carrier.

8; A centering guide for work pieces comprising a bracket, an adjustable slide on the bracket, guide plates carried by-thebra'cket and the slide in parallel spaced relationship, a pair of bell crank levers, a pivot bearing for each lever, a pair of spaced journals on the slide for saidbearings, said levers having horizontal arms with contiguous'free ends; a springattached to each arm, a clamp'forthe ends of the'springs, a depending arm'on each bellcranklever, a tension spring connecting said depen'ding'arms, anda guide plate on the end of each depending arm;

9; A' centering guide for work pieces comprising a support, a pair of"spaced journals on the support, a pair'of 'bell-crank'levers piv'otally carried in said journals, said levers havingfhorizontal arms with contiguous free ends, aspringattached to-each arm, a clamp for the ends of the springs, a dependingfarm on each bell crank lever, a tension springconnectingsaid depending arms and a guide plate on the end of each depending arm.

10. In a grinding machine of the type having annularly opposed abrasive discs for grinding parallel surfaces of a work piece, means for grinding equally on both surfaces comprising a pair of bell cranks pivotally mounted on horizontally spaced axes and having horizontal upper arms with the ends thereof adjacent one another and inclined lower arms, said lower arms each having a guide plate attached thereto, means connecting the lower arms for urging them toward one another, means connecting the horizontal arms whereby rotation of one arm will cause equal and opposite rotation of the other arm with corresponding movement of said guide plates toward or away from one another.

11. In a grinding machine of the type having annularly opposed abrasive discs for grinding parallel surfaces of a work piece, a work carrier comprising a workholder rotatably mounted for movement between the operative surfaces of said abrasive discs and having means thereon for carrying work pieces, means for holding said work pieces in said carrier comprising an endless chain suitably supported on said machine and movable into engagement with the peripheral surface of said carrier, means for centering said work pieces in said carrier comprising opposed guide plates and means for holding said plates at equal but variable distances from the center of the space between said abrasive discs including a pair of bell cranks mounted and connected so that movement of one causes an equal and opposite movement of the other whereby to accommodate variations in length or thickness of rough work pieces.

12. In a grinding machine of the type having annularly opposed abrasive discs for grinding parallel surfaces of a work piece, a work carrier comprising a workholder rotatably mounted for movement betweeen the operative surfaces of said abrasive discs and having means thereon for carrying work pieces, means for holding said work pieces in said carrier comprising an endless chain suitably supported on said machine and movable into engagement with the peripheral surface of said carrier, means for centering said work pieces in said carrier comprising opposed guide plates and means for holding said plates at equal but variable distances from the center of the space between said abrasive discs including a pair of bell cranks mounted and connected so that movement of one causes an equal and opposite movement of the other whereby to accommodate variations in length or thickness of rough Work pieces, said work holding chain engaging said work pieces at a point adjacent the point of exit of said work pieces from said guide plates.

13. A centering guide for work pieces comprising a support, a pair of spaced journals on said support, a pair of bell-crank levers pivotally carried on said journals, said levers having horizontal arms with contiguous free ends, connections between said ends whereby rotation of one of said levers on its journal will effect an identical movement of the other lever on its journal in the opposite direction, a depending arm on each bellcrank lever, a tension spring connecting depending arms and a guide plate on the endof each depending arm.

14 In a grinding machine of the type having annularly opposed abrasive discs, a carrier for conducting work pieces between said abrasive discs, a centering guide for maintaining the center line of Work pieces in line with the center of the space between said abrasive discs comprising a support, a pair of spaced journals on said support, a pair of levers pivotally mounted on said journals, said levers having horizontal arms with adjacent free ends, connections between said free ends-whereby rotation of one of said levers effects an identical rotation 'of the other lever but in the opposite direction, a depending arm on each lever, a guide plate on the end of each depending arm, and a tension spring connecting said depending arms for maintaining both of said guide plates in the same relation to the face of the adjacent abrasive disc regardless of the space between said guide plates as determined by the thickness of a work piece.

References Cited in the file of this patent UNITED STATES PATENTS 766,403 Vincke Aug. 2, 1904 1,965,020 Young July 3, 1934 FOREIGN PATENTS 415,044 Great Britain Aug. 7, 1934 

